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Unformatted text preview: intestine, and accessory glands. Excretory nephridia in each segment collect waste material from coelom and excrete it through the body wall. The Class Polychaeta Most annelids belonging to the taxonomic class Polychaeta are marine and possess parapodia and setae. Parapodia are paddlelike appendages used in swimming that also serve as respiratory organs. Setae are bristles, attached to parapodia, that help anchor polychaetes to their substratum and also help them move. Clam worms, such as Nereis, are active predators . Many have well-developed cephalization, with a head having well-developed jaws, eyes, and other sense organs. Sedentary filter feeders possess tentacles with cilia to create water currents and to select food particles. Only during breeding do polychaetes have reproductive organs. Polychaet zygotes develop into a type of larva similar to that produced by marine clams....
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This note was uploaded on 11/29/2011 for the course BIO BSC1010 taught by Professor Gwenhauner during the Fall '10 term at Broward College.
- Fall '10